Tetrahydrofuran → cis-2-methyl-7-octadecene
Reaction equation
[Mg].Cl[CH2:3][CH2:4]/[CH:5]=[CH:6]\[CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH3:16].[C:17]1(C)[CH:22]=CC(S(OCCC(C)C)(=O)=O)=[CH:19][CH:18]=1.[Cl-].[NH4+].O1CCC[CH2:36]1>>[CH3:16][CH:15]([CH2:14][CH2:13][CH2:12][CH2:11]/[CH:10]=[CH:9]\[CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:22][CH2:17][CH2:18][CH3:19])[CH3:36]Participants
Conditions
- Temperature
- -20 °C
Procedure
In a 1-liter reactor, a Grignard reagent was prepared from 5.0 g (0.206 mole) of magnesium and 46 g (0.2 mole) of 1-chloro-cis-3-tetradecene in exactly the same manner as in Example 4. Next, 100 g of tetrahydrofuran, 45.2 g (0.2 mole) of isoamyl p-toluenesulfonate and 0.5 g of cuprous iodide were placed in another 1-liter reactor and cooled to -20° C. Then, the above-described Grignard reagent was added dropwise thereto. After completion of the reaction, the mixture was stirred at 0° C. for 2 hours and then stirred without cooling until the temperature rose gradually to room temperature. Then, 100 g of a saturated aqueous ammonium chloride solution was added and the resulting mixture was allowed to separate into two layers. The organic layer was recovered and freed of solvent under reduced pressure. The resulting was distilled to obtain 16.1 g of 2-methyl-cis-7-octadecene (purity 96.0%, yield 62%, b.p. 155°-158° C./2 mmHg). MS(m/e): 56(100%), 266 (M+, 27%).
Workup
- customAfter completion of the reaction
- stirringstirred
- temperaturewithout cooling until the temperature
- customrose gradually to room temperature
- customto separate into two layers
- customThe organic layer was recovered
- distillationThe resulting was distilled
Sources & evidence
- ORD record
- ord-7aa6678c2f704b29afb1976dd5c0733f
- Source dataset
- uspto-grants-1998_02
- Patent number
- US05714649
Reaction notes
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